Question

Question 3 ! Please! I need help

Answer 1

To construct a perpendicular bisector  you set the compass to a span which is greater than half the length of the given line.  Then setting the point at one end of the line construct an arc  passing through the line . Then repeat this process from the other side of the line keeping the compass at the same setting.

Now draw the perpendicular  bisector through the 2 intersections of the arcs. That's  it.